Predominance of nano-scale effects observed in material behavior at
small scales requires implementation of new simulation methods which are
not merely based on classical continuum mechanic. On the other hand,
although the atomistic modeling methods are capable of modeling nano-
scale effects, due to the computational cost, they are not suitable for
dynamic analysis of nano-structures. In this research, we aim to develop
a continuum-based model for nano-beam vibrations which is capable of
predicting the results of molecular dynamics (MD) simulations with
considerably lower computational effort. In this classical-based
modeling, the surface and core regions are taken to have different
mechanical properties, where core atoms are assumed to have macroscale
properties whereas surface layer is showing a different elastic modulus
from the core components. By estimating physical parameters of proposed
classical model using molecular dynamics results and the genetic
algorithm, calibrated classical Euler-Bernoulli and Timoshenko beam
models are developed. The results demonstrates that a Timoshenko beam
model incorporating surface effects and having calibrated parameters, is
able to provide almost the same results as molecular dynamics method
which can be used to predict the vibrational behavior of nano-beams at
different scales from nano to macro. (C) 2015 Elsevier B.V. All rights
reserved.